WASHINGTON -- The chemical at the heart of the planet's most widely used herbicide -- Roundup weedkiller, used in farms and gardens across the U.S. -- is coming under more intense scrutiny following the release of a new report calling for a heightened regulatory response around its use. Critics have argued for decades that glyphosate, the active ingredient in Roundup and other herbicides used around the globe, poses a serious threat to public health. Industry regulators, however, appear to have consistently overlooked their concerns. A comprehensive review of existing data released this month by Earth Open Source, an organization that uses open-source collaboration to advance sustainable food production, suggests that industry regulators in Europe have known for years that glyphosate, originally introduced by American agricultural biotechnology giant Monsanto in 1976, caus...